Monthly Archives: June 2012

After Heart Attack, Which Is Better Diet: Low-Fat or Mediterranean?

Posted on June 30, 2012 | Comments Off on After Heart Attack, Which Is Better Diet: Low-Fat or Mediterranean?

For the last 12 years, the answer has been “Mediterranean.”  But a new study challenges that conclusion.

By the way, “diet” in this blog post refers to “a habitual way of eating” rather than a weight-loss program.

Researchers at The Heart Institute of Spokane (Washington) set out to compare the effects of a Mediterranean-style diet and a conventional “heart-healthy” low-fat diet in people who had suffered a heart attack within the last six months.  To test whether diet intervention per se had any effect, a “usual-care” group of patients (101 participants) was also studied.

Methodology

Dietary intervention participants were randomized to either:

  1. A low-fat diet (American Heart Association Step II) (50 participants).  Main goals were to reduce cholesterol intake to under 200 mg/day and saturated fat to under 7% of total calories, or
  2. A Mediterranean-style diet (51 participants) with the same cholesterol and saturated fat goals, plus an increased intake of omega-3 fatty acids (to over 0.75% of calories) and monounsaturated fats (to 20-25% of calories).  Emphasis was on consumption of cold-water fish 3-5 times per week, and on oils from olives, soybeans, and canola.

Both diets encouraged intake of fresh fruits and vegetables – at least 5 servings a day – and whole grains.  Loss of excess weight was not a goal.

Diet intervention participants were given two individual counseling sessions with a dietitian within the first month, with additional sessions at months 3, 6, 12, 18, and 24.  Participants also attended six group sessions.  Three-day food diaries were examined periodically to assess compliance with dietary recommendations.  Various lipids and omega-3 fatty acids were measured in plasma.  I assume that judicious wine consumption was at least mentioned as part of the Mediterranean diet, but actual intake was not reported.

The “usual-care” group, also known as controls, “received dietary advice from medical center dietitians.  American Heart Association Step II guidelines were presented as a nutrition class or video and written materials.”  Just one presentation, apparently.

All participants were followed on average for almost four years.  “The primary outcome [emphasis added] was a composite of end points including all-cause and cardiac deaths, myocardial infarction, hospital admission for heart failure, unstable angina, or stroke.”  Obviously,  you want to avoid these primary outcome end points.

Results

  • Avoidance of the primary outcome end points was the same in both the low-fat and Mediterranean diet groups.  Each intervention group had eight primary outcome end points.
  •  Forty of the 101 people in the usual care group suffered one or more of the primary outcome end points.  Only 16 of the 101 dietary intervention patients suffered one or more of the primary outcome end points.  Compared to the usual care group, the dietary intervention patients were only one-third as likely to suffer cardiac death, death from any cause, heart attack, hospital admission for heart failure, unstabe angina, or stroke.  This is a significant difference.
  • Goals for cholesterol, saturated fat, and omega-3 intake were achieved, or nearly so, in the dietary intervention groups.
  • Neither diet intervention group lost weight.
  • After two years, there were no differences between low-fat and Mediterranean groups in terms of HDL cholesterol, LDL cholesterol, triglycerides, and fasting glucose.
  • Among the diabetics (10 in each intervention group), there were no differences in fasting glucose.
  • The drop-out rate was low.

Take-Home Points

In the researchers’ words:

[This study] demonstrates that low-fat and Mediterranean-style diets can be similarly effective strategies for therapeutic lifestyle change, particularly when applied with equal intensity of intervention.

[This study] highlights the importance of heart-healthy diets in patients who have recently had [heart attacks].  The 2 intervention groups had relatively low intakes of cholesterol and saturated fat, but only Mediterranean-style diet partipants increased omega-3 fat consumption.  Because neither cardiovascular events nor risk factors differed between interventions , [this study] does not substantiate claims that increased omega-3 fat intake, predominantly from eating fish, adds benefit beyond a diet emphasizing reduced cholesterol and saturated fat.

The authors admit that the small number of participants is a weakness of their study.

They also cite another study, Medi-RIVAGE, that tends to support their findings.  Yet the Medi-RIVAGE “data predicted a 9% reduction in cardiovascular disease risk with the low-fat diet and a 15% reduction with this particular Mediterranean diet.”  According to the Medi-RIVAGE study abstract, “After a 3-mo intervention, both diets [low-fat and Mediterranean] significantly reduced cardiovascular disease risk factors to an overall comparable extent.”

The seeming equality of the low-fat and Mediterranean diets is a surprise to me.  I would have predicted superiority of the Mediterranean diet.  Alcohol and nut consumption have been associated with improved cardiovascular outcomes in several observational studies.  I wonder if these two intervention groups had the same or different consumption of alcohol and nuts.

But these researchers may be on to something here.  That is,  low-fat and Mediterranean diets – with intensive dietary instruction – are equally good diet interventions for preventing future cardiac events in people who have had a recent heart attack.  Dr. Dean Ornish’s vegetarian program might also stack up well against these two diets and “usual care.”

Before I abandon my preference for the Mediterranean diet in prevention of cardiac disease, I’d like to see the findings of this study confirmed by a larger one.  In addition to cardiovascular benefits, the Mediterranean diet is associated with:

No diet other than the Mediterranean can legitimately claim all these benefits.  And it tastes good.

Steve Parker, M.D.

References:

Tuttle, Katherine R., et al.  Comparison of Low-Fat Versus Mediterranean-Style Dietary Intervention After First Myocardial Infarction (from The Heart Institute of Spokane Diet Intervention and Evaluation Trial).  American Journal of Cardiology, 101 (2008): 1,532-1,531.

Vincent-Baudry, Stephanie, et al.  The Medi-RIVAGE study: reduction of cardiovascular disease risk factors after a 3-mo intervention with a Mediterranean-type diet or a low-fat diet.  American Journal of Clinical Nutrition, 82 (2005): 964-971.

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Posted in Coronary Heart Disease, Diet Reviews

Alcohol Habit (Especially Wine) Starting in Middle-Age Reduces Heart Attack and Stroke

Posted on June 28, 2012 | 3 comments

Jesus turned water into wine at a wedding.  His mother asked him to do it.  Of all the miracles he performed and could have performed, I wonder why this is the first one recorded in the Holy Bible.

We have known for years that low or moderate alcohol consumption tends to lower the risk of cardiovascular disease such as heart attack and stroke, and prolongs life span.  Physicians have been hesitant to suggest that nondrinkers take up the habit.  We don’t want to be responsible for, or even accused of, turning someone into an alcoholic.  We don’t want to be held accountable for someone else’s drunken acts.  Every well-trained physician is quite aware of the ravages of alcohol use and abuse.  We see them up close and personal in our patients.

A scientific study from a few years ago, however, lends support to a middle-aged individual’s decision to start consuming moderate amounts of alcohol on a regular basis.  It even provides a positive defense if a doctor recommends it to carefully selected patients.

This research, by the way, was supported by a grant from the National Heart, Lung, and Blood Institute, not the wine/alcohol industry.

Methodology

Researchers at the Medical University of South Carolina examined data on 15,637 participants in the Atherosclerosis Risk in Communities (ARIC) study over a 10-year period.  These men and women were 45 to 64 years old at the time of enrollment, living in four communities across the U.S.  Of the participants, 27% were black, 73% nonblack, 28% were smokers, and 80% of them had high blood pressure, high cholesterol, or diabetes.

Out of 15,637 participants at the time of enrollment, 7,359 indicated that they didn’t drink alcohol.  At baseline, these 7,359 had no cardiovascular disease except for some with high blood pressure.    Subsequent interviews with them found that six percent of the nondrinkers – 442 people – decided independently to become moderate alcohol drinkers.  Or at least they identified themselves as such.

“Moderate” intake was defined as 1-14 drinks per week for men, and 1-7 drinks a week for women.  Incidentally, 0.4% of the initial non-drinking cohort – 21 people – became self-identified heavy drinkers.

93.6% of the 7,359 non-drinkers said that they continued to be non-drinkers.  These 6,917 people are the “persistent nondrinkers.”

Type of alcohol consumed was also surveyed and broken down into 1) wine-only drinkers, or 2) mixed drinkers: beer, liquor, wine.

Researchers then monitored health outcomes for an average of 4 years, comparing the “new moderate drinkers” with the “persistent nondrinkers.”

Results

  •  Over 4 years, 6.9% of the new moderate drinkers suffered a cardiovascular event, defined as a heart attack, stroke, a coronary heart disease procedure (e.g, angioplasty), or death from cardiovascular disease.
  • Over 4 years, 10% of the persistent nondrinkers suffered a cardiovascular event.
  • The new moderate drinkers were 38% less likely than persistent nondrinkers to suffer a new cardiovascular event (P = 0.008, which is a very strong association).  The difference persisted even after adjustment for demographic and cardiovascular risk factors.
  • There was no difference in all-cause mortality (death rate) between the new moderate drinkers and the persistent nondrinkers.
  • New  drinkers had modest but statistically significant improvements in HDL and LDL cholesterol and mean blood pressure compared with persistent nondrinkers.
  • 133 new moderate drinkers consumed only wine
  • 234 new moderate drinkers consumed mixed types of alcohol
  • Wine-only drinkers were 68% less likely than nondrinkers to suffer a cardiovascular event.
  • “Consumers of moderate amounts of beer/liquor/mixed (which includes some wine) tended to also be less likely to have had a subsequent cardiovascular event than nondrinkers…but the difference was not significant.”

A Few Study Limitations

  • Four years is a relatively brief follow-up, especially for cancer outcomes.  Alcohol consumption is associated with certain types of cancer.
  • If moderate alcohol consumption indeed lowers death rates as suggested by several other studies, this study may not have lasted long enough to see it.
  • The alcohol data depended on self-reports.

Take-Home Points

The study authors cite four other studies that support a slight advantage to wine over other alcohol types.  It’s a mystery to me why they fail to stress the apparent superiority of wine in the current study.  Several other studies that found improved longevity or cardiovascular outcomes in low-to-moderate drinkers suggest that the type of alcohol does not matter.  Perhaps “the jury is still out.”  In the study at hand, however, it is clear that the reduced cardiovascular disease rate in new moderate drinkers is associated with wine.

In all fairness, other studies show no beneficial health or longevity benefit to alcohol consumption.  But at this point, the majority of published studies support a beneficial effect.

Wine is a component of the traditional healthy Mediterranean diet.  The Mediterranean diet is associated with prolonged life span and reduced cardiovascular disease.  This study strongly suggests that wine is one of the causative healthy components of the Mediterranean diet.

Starting a judicious wine habit in middle age is relatively safe for selected people and may, in fact, improve cardiovascular health, if not longevity.

Now the question is, red or white.  Or grape juice?

Steve Parker, M.D.

Reference:  King, Dana E., et al.  Adopting Moderate Alchohol Consumption in Middle Age: Subsequent Cardiovascular Events.  American Journal of Medicine, 121 (2008): 201-206.

3 Comments

Posted in Alcohol, Coronary Heart Disease, Stroke, Uncategorized

First New Weight-Loss Drug in a Decade: Lorcaserin Hydrochloride

Posted on June 27, 2012 | 1 comment

The U.S. Food and Drug Administration today approved lorcaserin hydrochloride as a weight-loss drug, according to MedPage Today.

The drug, to be sold as Belviq in the U.S., is an activator of the serotonin C2 receptor in the brain.  This may reduce food consumption by producing early satiety at mealtime.

According to the FDA’s press release, “the most common side effects of Belviq in non-diabetic patients are headache, dizziness, fatigue, nausea, dry mouth, and constipation, and in diabetic patients are low blood sugar (hypoglycemia), headache, back pain, cough, and fatigue.”

I rarely prescribe weight-loss drugs for my patients.  They’re expensive.  They have side effects.  They’re not very effective.  And when you stop the drug, the fat returns.

Steve Parker, M.D.

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Huge Study Confirms Health and Longevity Benefits of Mediterranean Diet

Posted on June 27, 2012 | Comments Off on Huge Study Confirms Health and Longevity Benefits of Mediterranean Diet

Italian researchers reported in the September 11, 2008, online issue of the British Medical Journal what is already known:

“Greater adherence to a Mediterranean diet is associated with a significant improvement in health status, as seen by a significant reduction in overall mortality (9%), mortality from cardiovascular diseases (9%), incidence of or mortality from cancer (6%), and incidence of Parkinsons’s disease and Alzheimer’s disease (13%).  These results seem to be clinically relevant for public health, in particular for encouraging a Mediterranean-like dietary pattern for primary prevention of major chronic diseases.”

Methodology

Researchers, mostly at the University of Florence, performed a meta-analysis of 12 other published studies that looked at the effects of a Mediterranean-style eating pattern on health and longevity.  [Meta-analyses are popular, in part, because they are cheap.  This study required no specific funding.]

Most, if not all, of these 12 studies were observational, and involved 1,574,299 participants.  Six of the 12 studies were in Mediterranean countries, the others were in the U.S., northern Europe, and Australia.  Study participants were followed between 3.7 and 18 years.

The researchers devised their very own Mediterranean diet scale based on study participants’ intake of various foods.  Participants were given a point if they had higher than average intake of vegetables, fruits, legumes, cereals, fish, and red wine during meals.  They were given a point if they had lower than average intake of red meat, processed meats, and dairy products.  Due to differences among the 12 studies, “the total adherence scores…varied from a minimum of 0 points indicating low adherence to a maximum of 7-9 points reflecting high adherence to a Mediterranean diet.”

(This version of a Mediterranean diet score is problematic.  Curiously, olive oil – the predominant source of fat in the traditional Mediterranean – is not in the score.  Olive oil is a key characteristic of the Mediterranean diet.  Furthermore, the study authors also state that dairy products are “presumed not to form part of a Mediterranean diet.”  Most experts would argue that cheese and yogurt are a significant part of the Mediterranean diet, if only in low amounts.  I also doubt that participants in the 12 original studies  were surveyed whether they drank red wine – as contrasted with white – and whether it was with meals or not.  I admit I did not read each of the 12 component studies.  The underlying cause of this idiosyncratic definition of the Mediterranean diet is that the 12 original studies themselves used different definitions of the Mediterranean diet.  The meta-analysts had to pigeonhole the data.  There are a handful of respected Mediterranean diet scores in existence, but the authors of this study couldn’t apply them across the board due to database inconsistency or inadequacy.)

Results

“The cumulative analysis of 12 cohort studies shows that a two point increase [emphasis added] in the score for adherence to a Mediterranean diet determines a 9% reduction, in overall mortality, a 9% reduction in mortality from cardiovascular diseases, a 6% reduction in incidence of or mortality from neoplasm [cancer], and 13% reduction in incidence of Parkinson’s disease and Alzheimer’s disease.”

The only one of the 12 original studies focused on Alzheimer’s disease, and it showed a 17% reduction in participants with high adherence to the Mediterranean diet.  The two studies that focused on Parkinson’s disease revealed a 7% reduction in men, and 15% reduction in women.  These reduced incidence figures, again, apply to a two-point increase in Mediterranean diet adherence score.

Discussion

The authors indicate that their report is the first ever meta-analysis of the data associating the Mediterranean diet with reduced mortality and chronic disease in the general population.  Congratulations, guys!

The authors’ idiosyncratic Mediterranean diet score is unusual and won’t be widely adopted.  However, the 12 studies comprising the meta-analysis did have reasonable Mediterranean diet characteristics.

Combining Alzheimer’s data with Parkinson’s data doesn’t make sense to me, nor did the authors try to explain it.   You could lump them into the category of “neurodegenerative diseases,” but they aren’t the only ones by any means.  The single Alzheimer’s study, by the way, was quite small compared to the two Parkinson’s studies.

Nearly all the popular media stories reported the findings as I did in my first paragraph above, which may be  misleading.  The specific improvements in mortality and various disease rates is per two-point increase in Mediterranean diet score.  For example, consider the 9% reduction in overall mortality.  If a population increased its Mediterranean score by four points, would overall mortality be reduced by 18%?  I’ve read this study four times and cannot answer my own question.  But I suspect that the answer is “yes.”  So the news here may better than it seems at first blush.

In other words: If a population’s score goes from 5 to 7, the death rate is reduced by 9%.  If that same population then moved its score from 7 to 9, would mortality improve another 9%?  I think so, but this study as written does not make it clear.

I’m starting to see why the popular media simplified the study findings.  The reporting on this study is amazingly uniform.  They must have all gotten the same news release.

Of course, “populations” don’t die or get cancer, heart attacks, strokes, Alzheimer’s, or Parkinson’s disease.  Individuals do that.  If I as an individual had a low Mediterranean diet score, I’d try to improve my score by at least two points.  A good place to start would be a review of the Mediterranean diet.

Steve Parker, M.D.

Reference:  Sofi, Francesco, et al.  Adherence to Mediterranean diet and health status: Meta-analysis.  British Medical Journal, 337; a1344.  Published online September 11, 2008.  doi:10.1136/bmj.a1344

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Posted in Alzheimer Disease, Cancer, Coronary Heart Disease, Dementia, Heart Disease, Longevity

Quote of the Day

Posted on June 25, 2012 | Comments Off on Quote of the Day

Adult diapers outsold baby diapers in Japan last year for the first time ever.

— Morgan House in an article at The Motley Fool

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Quote of the Day

Posted on June 25, 2012 | Comments Off on Quote of the Day

A tip for guys who like to wear speedos. It helps to carry a potato in your speedo. But make sure you wear it in the front.

— Keaton (comment No.23)

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Posted in Quote of the Day, Uncategorized

Is Exercise Important for Maintenance of Weight Loss In Women?

Posted on June 24, 2012 | Comments Off on Is Exercise Important for Maintenance of Weight Loss In Women?

This news is a bit stale, but I wanted my readers to be sure to see it.

An article in the July 28, 2008, issue of Archives of Internal Medicine teaches us the role of regular physical activity in keeping lost weight from returning to once-overweight women.

Methodology

201 overweight women (body mass index 27-40) aged 21 to 45 wanted to lose excess weight.  They were sedentary at baseline, exercising fewer than three days a week for under 20 minutes.  Sound familiar?  Depending on baseline weight, the participants were assigned to eat either 1200 or 1500 calories per day, and to exercise according to one of four different exercise programs.  Exercise recommendations were to burn a certain number of calories per week (1000 or 2000 calories) at either moderate or vigorous intensity.  There were weekly group meetings for discussion of eating and exercise for the first six months, twice monthly meetings during the next 6 months, and monthly for the next six months.  There was telephone contact for between months  19 to 24.  This is pretty intense contact.  Each participant was given a treadmill to use at home, but my impression is that other forms of exercise were permitted and discussed.

Ten subjects were excluded from follow-up analysis, mostly because they got pregnant.  Nineteen others lost interest and dropped out.

Participants self-reported their physical activity levels.

At 24 months into the study, 170 of the original 201 participants were able to provide objective weight loss data.

Findings

Of the 170 subjects available for full analysis at 24 months, 54 either gained weight or lost none.  Thirty-three lost 0 to 4.9% of initial body weight, 36 lost 5 to 9.9% initial body weight, and 47 (24.6%) lost 10% or more of initial body weight.  [Who says diets don’t work?]

People who lost 10% or more of initial body weight at 24 months reported performing more physical activity – 275 minutes a week – compared with those who lost less than 10% of initial body weight.  This amount of exercise equates to 55 minutes of exercise on five days per week above the baseline level of activity, which was sedentary as you recall.  Whether they were assigned to “moderate” or “vigorous” exercise intensity didn’t seem to matter.  Whether they actually performed at the assigned level is unclear.

These women who sustained a weight loss of 10% or more of initial body weight at 24 months were burning 1835 calories a week in physical activity.

Women who lost less than 10% of initial body weight, or lost no weight, exercised an average of 34 minutes a day on five days a week.

By 24 months, participants on average had regained about half of the weight they had lost during the first six months  [which is typical].

Take-Home Points

After six months of dieting, many people start to regain half of what they lost.  We saw this phenomenon in the Israeli study of low-fat vs low-carb vs Mediterranean diet (DIRECT trial).

If you have a lot of excess fat to lose, you have to wonder if it would make sense to start a different diet program every six months, until you reach your weight goal.  Maybe there’s something about the novelty and excitement of a new diet program that keeps you motivated and disciplined for six months.

The authors note there are few similar long-term studies examining the amount and intensity of physical activity needed to improve weight loss success.  So this is important information.

In using exercise to help prevent weight regain, it may not matter whether the exercise is moderate or intense.

The authors write:

…the inability to sustain weight loss appears to mirror the inability to sustain physical activity.

Long-term sustained weight loss is possible for a significant portion of overweight women.  Although most women won’t do it, success is enhanced by exercising for 55 minutes on five days a week.  Most men won’t exercise that much either.  Which camp do you fall into?

[For physical activity instruction and information, visit Shape Up America!, Physical Activity for Everyone, or Growing Stronger: Strength Training for Older Adults.]

Steve Parker, M.D.

Reference:  Jakicic, John M., et al.  Effect of Exercise on 24-Month Weight Loss Maintenance in Overweight Women.  Archives of Internal Medicine, 168 (2008): 1,550-1,559.  

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Posted in Exercise, Uncategorized, Weight Loss, Weight Regain

Are We Fat Because We Eat Too Much, Or Lack Physical Activity?

Posted on June 22, 2012 | Comments Off on Are We Fat Because We Eat Too Much, Or Lack Physical Activity?

Are we fat because we eat too much, or lack physical activity?

Most people would say, “It’s both.” Most people would be wrong, at least in terms of populations rather than individuals.

Obesity results from a protracted imbalance between energy intake (calories we eat) and energy expenditure (physical activity and resting metabolism).

Overweight and obesity have increased significantly over the last 25 years in most of the developed world. Is it because we started eating more, or that we have so many energy-saving devices that we now expend less energy on physical activity? If we are less active due to technologic advances, yet keep eating as much as in the past, we will gain weight as the excess calories are stored as fat.

Technologic advances over the last 150 years have allowed us to transform from a labor-intensive agrarian economy to one based on services and information. Computers, in particular, have made it much less labor-intensive to get our jobs done. For example, when I was a hospital intern 30 years ago, I made multiple daily trips from the patient care floors downstairs to Radiology to look at x-ray films. Now, the “films” are at my fingertips on computers close to the bedside.

Have trends in technology over the last 25 years continued to reduced the energy expenditure needed to get through our days? Alternatively, are we exercising less? Either explanation would lead to weight gain if caloric intake remained the same.

Researchers in 2008 studied populations in Europe and North America, examining trends in physical activity energy expenditure over time, since the 1980s. Energy expenditure was evaluated with a highly accurate method called “doubly labelled water.” They found that physical activity energy expenditure actually increased over time, although not by much. They conclude that the ballooning waistlines in the study populations are likely to reflect excessive intake of calories.

(All I have is the abstract of the article. I’ll try to get the full article and report back here if anything additional is interesting.)

So according to Westerterp and Speakman, the problem has not been lack of physical activity. We’re simply eating too much.

On the other hand, a 2011 study found that daily work-related energy expenditure decreased by over 100 calories in the U.S. over the last 50 years.  That could certainly contribute to our expanding waistlines.

Steve Parker, M.D.

Reference: Westerterp, K.R., and Speakman, J.R. Physical activity energy expenditure has not declined since the 1980s and matches energy expenditures of wild mammals. International Journal of Obesity, 32 (2008): 1256-1263. Published online May 27, 2008. doi: 10.1038/ijo2008.74

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The Role of Exercise in Maintenance of Weight Loss In Women

Posted on June 21, 2012 | 2 comments

A 2008 article in Archives of Internal Medicine teaches us the role of regular physical activity in keeping lost weight from returning to once-overweight women.

Methodology

201 overweight women (body mass index 27-40) aged 21 to 45 wanted to lose excess weight. They were sedentary at baseline, exercising fewer than three days a week for under 20 minutes. Sound familiar? Depending on baseline weight, the participants were assigned to eat either 1200 or 1500 calories per day, and to exercise according to one of four different exercise programs. Exercise recommendations were to burn a certain number of calories per week (1000 or 2000 calories) at either moderate or vigorous intensity. There were weekly group meetings for discussion of eating and exercise for the first six months, twice monthly meetings during the next 6 months, and monthly for the next six months. There was telephone contact for between months 19 to 24. This is pretty intense contact. Each participant was given a treadmill to use at home, but my impression is that other forms of exercise were permitted and discussed.

Ten subjects were excluded from follow-up analysis, mostly because they got pregnant. Nineteen others lost interest and dropped out.

Participants self-reported their physical activity levels.

At 24 months into the study, 170 of the original 201 participants were able to provide objective weight loss data.

Findings

Of the 170 subjects available for full analysis at 24 months, 54 either gained weight or lost none. Thirty-three lost 0 to 4.9% of initial body weight, 36 lost 5 to 9.9% initial body weight, and 47 (24.6%) lost 10% or more of initial body weight. (Who says diets don’t work?)

People who lost 10% or more of initial body weight at 24 months reported performing more physical activity – 275 minutes a week – compared with those who lost less than 10% of initial body weight. This amount of exercise equates to 55 minutes of exercise on five days per week above the baseline level of activity, which was sedentary as you recall. Whether they were assigned to “moderate” or “vigorous” exercise intensity didn’t seem to matter. Whether they actually performed at the assigned level is unclear.

These women who sustained a weight loss of 10% or more of initial body weight at 24 months were burning 1835 calories a week in physical activity.

Women who lost less than 10% of initial body weight, or lost no weight, exercised an average of 34 minutes a day on five days a week.

By 24 months, participants on average had regained about half of the weight they had lost during the first six months [which is typical].

Take-Home Points

After six months of dieting, many people start to regain half of what they lost. We saw this phenomenon recently in the Israeli study of low-fat vs low-carb vs Mediterranean diet.

If you have a lot of excess fat to lose, you have to wonder if it would make sense to start a different diet program every six months, until you reach your weight goal. Maybe there’s something about the novelty and excitement of a new diet program that keeps you motivated and disciplined for six months.  For someone with lots of weight to lose, I wonder if they’d do better switching to a new diet every six months.

The authors note there are few similar long-term studies examining the amount and intensity of physical activity needed to improve weight loss success. So this is important new information.

In using exercise to help prevent weight regain, it may not matter whether the exercise is moderate or intense.

The authors write:

…the inability to sustain weight loss appears to mirror the inability to sustain physical activity.

Long-term sustained weight loss is possible for a significant portion of overweight women. Although most women won’t do it, success is enhanced by exercising for 55 minutes on five days a week. Most men won’t exercise that much either. Which camp do you fall into?

For physical activity instruction and information, visit Shape Up America!, Physical Activity for Everyone, or Growing Stronger: Strength Training for Older Adults.

Steve Parker, M.D.

Reference: Jakicic, John M., et al. Effect of Exercise on 24-Month Weight Loss Maintenance in Overweight Women. Archives of Internal Medicine, 168 (2008): 1,550-1,559.

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Prostate Cancer Deaths Linked to Overweight and High Insulin Levels

Posted on June 20, 2012 | Comments Off on Prostate Cancer Deaths Linked to Overweight and High Insulin Levels

Lancet Oncology in 2008 published a report associating worse prostate cancer outcomes—death, that is—with overweight, obesity, and hyperinsulinemia.

Grapes are an iconic Mediterranean fruit

Researchers looked at data from the respected Physicians’ Health Study, finding 2,546 men who developed prostate cancer during many years of observation. Of these men, 38.8% were overweight (body mass index 25–30) and 3.4% were obese (BMI over 30).

(For definitions of overweight and obesity, and to calculate your body mass index, click here.)

Compared with normal-weight men (BMI under 25) who developed prostate cancer, overweight men with prostate cancer were one-and-a-half times more likely to die from the cancer. Obese men with prostate cancer were two-and-a-half times more likely to die.

A blood test called C-peptide is a marker of insulin resistance and hyperinsulinemia. Obesity is often accompanied by high insulin levels and insulin resistance. Overweight, not so much. Eight hundred twenty-seven of the men with prostate cancer had C-peptide levels drawn at baseline, before diagnosed with cancer. Men with the highest C-peptide levels were almost two-and-a-half times more likely to die of prostate cancer than men with the lowest C-peptide levels.

Study participants having both excess body weight and high C-peptide levels had the worst outcome.

Prostate cancer is the most common invasive cancer in U.S. men, with about 185,000 cases diagnosed every year. It is one of the cancers that can be prevented by following the traditional Mediterranean diet for years. The other prevented cancers are breast, uterus, and colorectal. Obesity predisposes men to cancer of the prostate, colon, rectum, kidney, and esophagus.

The study at hand suggests that if you are overweight or obese and then develop prostate cancer, you have a greater risk of dying from the cancer compared with healthy-weight men. Given that prostate cancer is so common, why not cut your risk of getting it and dying from it by controlling your weight with a Mediterranean-style diet?

Steve Parker, M.D.

Reference: Ma, Jing, et al. Prediagnostic body mass index, plasma C-peptide concentration, and prostate cancer-specific mortality in men with prostate cancer: a long-term survival analysis. Lancet Oncology, online publication October 6, 2008. DOI: 10.1016/S1470-2045(08)70235-3

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